Analyzing mechanism



June 3, 1941.v o. WEITMANN 2,244,228

ANALYZ ING MECHANISM Filed June 8, 1939 2 Sheets-Sheet l i5. 2 PAPER-AFTER aurn/va TTWT'TFZ M PAPER BEFORE surmva 2 i FIYENTOR ATTORNEY vJune 3, 1941. o. WEITMANN 2,244,228

ANALYZING MECHANISM Filed June 8, 1939 2 Sheets-Sheet 2 POWER SUPPLY 0+ INVENTOR ATTORNEY Patented June 3, 1941 ANALYZING MECHANISM Otto Weitmann, Johnson City, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application June 8, 1939, Serial No. 277,972

1 Claim.

This invention relates to a sensing device and more particularly to sensing devices adapted to detect certain impurities formed in paper webs which in the finished product are in the form of translucent areas or spots.

Such areas or spots destroy the normal uniform cohesive characteristics of the paper, and since such spots, which in the paper manufacturing art are known as slime spots, fail to adhere strongly to the surrounding area of the paper they readily can become dislodged from the paper, especially when a local force is applied to an area in the paper which is in close proximity to such spots.

It is known that paper stock with perfect insulating characteristics is necessary to produce tabulating cards for use in electrical statistical machines. Such machines, for example those based on the Hollerith principle, are controlled by perforated cards, the perforations thereof representing certain data and facts which are to be tabulated by the machines. Electrical sensing circuits embodying sensing brushes control the tabulating circuits in accordance with the perforations disposed on the record cards. The imperforate areas of the cards maintain the sensing circuits open as the cards are fed past the sensing brushes, whereas the perforate areas permit the sensing brushes to complete the sensing circuits of the statistical machines.

However, if unwanted perforate areas were present in the record cards. erroneous energization of the sensing circuits would occur and thus cause I faulty operations of the machines.

It has been found that during perforating operremoval of such faulty sections from the paper webs or facilitate the detection of a card containing a faulty section from a plurality of tabulating cards produced.

In practice the manufactured paper is produced in rolls the width of which is greater than the standard width of a tabulating card, therefore, the paper is fed from such rolls to a suitable paper slitting device which is adapted to slit the single web into a plurality of webs the widths of which are equivalent to the width of a tabulating card. Before the single paper web is fed to the slitting device, it must be tested for various impurities including the slime spots referred to. Briefly, the procedure for detecting the slime spots is as follows: The paper web is fed past a suitable light source disposed on one side of the paper web and a light sensitive unit disposed on the other side of the web, the said unit comprising an opaque frame member having a suitable light transmitting section formed therein which extends across the width of the paper web and a photocell disposed behind the frame member so that it is directly in line with the said light transmitting section and light source. In the event of certain foreign spots formed in the paper to be tested; these spots when fed past the detecting device cause the amount of light impinging on the photocell to be changed thereby causing a change in the value of the current impressed upon the associated amplifier system and in turn causing a control relay to be energized. The energization of the relay can then control the operation of a suitable paper marking device so as to mark the spots or areas including the foreign spots detected.

Therefore, one of the objects of the present invention is the provision of means whereby foreign spots can be detected in a web of material, the detection of said spots effected by modulating rays of light so that the changes of light impinged upon a light sensitive device is effective to condition the device and cause an indicating unit to be operated to mark the areas of the web including the said spots.

Other objects of the invention will be pointed out in the following description and claim and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig, 1 is an end view of the device showing the disposition of the detecting and indicating units.

Fig. 2 is a detail view showing the arrangement of the apertures in the opaque frame member.

Fig. 3 is a detail view of another type of sensing grill.

Fig. 4 is the circuit diagram of the device.

Fig. 5 is a side view of the card marking solenoid.

Fig. 6 is a detail view of the solenoid.

Referring now to Fig. 1, it is shown how the paper web HI is fed from a supply roll S by means of suitably driven rollers ll. past the sensing apertures I2 formed in an opaque frame member I3. Suitably disposed on the other side of the paper web is a light source such as the lamp I4 and reflector I5. In Fig. 2 the sensing apertures I2 are shown to be arranged end to end so as to sense completely the entire width of the paper web. The said apertures are also shown staggered vertically so as to allow sufficient space to mount the photocells I6 in back of the frame member l3 and directly opposite the sensing apertures. In the present illustration, eight sensing apertures are shown disposed across the width of the paper web since in practice, in making tabulating cards the paper web is slit into eight sections as indicated in the figure. The slitting device is not shown since it forms no part of the present invention.

It is understood that in such cases where a plurality of sensing apertures are employed, individual photocells are used; each photocell is preferably elongated so as to correspond to the width of the aperture. A common light source 'or individual sources may be used depending upon the type of application of the detecting device. Each photocell is provided with a window corresponding to the size of the sensing aperture which is disposed directly opposite the aperture, in this manner stray light rays are prevented from impinging on the photocells. A suitable amplifying section I! (Fig. 4) is provided for .each photocell which can be suitably mounted directly above the photocells as shown in Fig. 1. Suitably mounted above the amplifying section is the indicating device comprising a printing solenoid I8 and relays R-l and R-2 (also see Fig. 4). The printing solenoid is shown disposed in close proximity to the paper web l9 which is fed continuously therepast. Upon energization of the solenoid the wick [9 will be caused to engage the section of the paper web opposite it and print an indicating mark or stripe on the section of the paper web including the foreign spot or spots.

Before describing the control circuit, the printing solenoid shown in Figs. and 6 will be described. The coil is shown to be formed on a sleeve 2I which is supported by the yoke 22. A plunger 23 formed from hollow tubing having varying diameters is shown inserted in the sleeve 2|, the inside diameter D is shown to be greater than diameter d. One end of the plunger 23 is provided with a wick l9 and the other end with a cap screw 24. The entire plunger may be filled with a printing fluid. To fill the plunger the wick can be adapted to be removed from the plunger for this purpose, or if desired a narrow slot 21 may be provided on the top side of the plunger through which the fluid can be poured. A plunger stop ring 25 is provided and determines the displacement of the plunger. Near the end of the plunger, stroke to the left as viewed in Fig. 5 the stop ring is adapted to engage the contacts 0 which are mounted on the yoke 22 by means of the supporting member 26. Further displacement of the plunger to the left causes the said contacts to be opened, the purpose of which will be explained presently,

Referring now to Fig. 4 the photocell amplifying section I1 is shown to comprise three stages of amplification including the electron devices T--I to T-3 connected in a well known cascade arrangement. The device 'I'3 is biased or con ditioned so that normally the said device is nonin the plate circuit 01 the-device T-3 and normally is deenergized. The amplifier is conditioned so, that when the rays of light, which are permitted to pass through the paper web, are normally impinging on the photocell (through the associated sensing aperture), the output of the said amplifier remains unaffected. However, assume now that slime spot or similar foreign substance formed in the paper web is fed past one of the sensing apertures; it is evident that the amount of light impinging on the photocell is changed. For the illustration chosen the slime spot being more translucent than the paper web permits a greater amount oi! light to impinge on the photocell as the spot is fed past the sensing aperture. This difference in the amount of light impinged on the photocell is effective to condition the amplifier so that current flows in the output circuit thereof as long as the spot appears before the sensing aperture. In this manner relay R-l is energized causing the associated contacts RIa to be closed. A circuit is then completed from the positive terminal of the power supply, to contacts Rla, coil of relay R,2 to the negative terminal of said supply, energizing the said relay. The relay R-I is a fast acting relay and remains energized only as long as the output circuit of the amplifier unit remains energized. Therefore a holding circuit for relay R2 is provided which can be traced from the positive terminal of the power supply to the normally closed contacts C, contacts R--2a (now closed) coil of relay R-2 to the negative terminal of the said supply, maintaining the said relay energized as long as contacts C remain closed. Upon closure of the contacts R2b associated with relay R-Z the printing solenoid I8 conductive. The coil of relay R.-I is connected is energized by the circuit from the positive terminal of the power supply, coil of the solenoid I8, contacts R2b to the negative terminal of the said supply. Upon energization of the solenoid the plunger 23 thereof carrying the wick I5 is caused to engage the paper web and print a mark or stripe-over the section of the paper web including the slime spot. When the solenoid plunger has been fully displaced the associated contacts C are opened which causes the holding circuit for relay R--2 to be opened, thus effecting deenergization of the relay R-2 and solenoid I8.

The characteristics of the solenoid circuit are chosen so that the electrical lag in this circuit is suflicient so that the printing of the mark by the solenoid plunger is not eifected until the particular section of the paper web containing the slime spot is adapted to be fed to the printing plunger. It is assumed for the present desoription that the resistance and inductance values of the solenoid coil are such as to provide sufiicient electrical lag in the solenoid circuit and thereby permitting the detected spot to be fed from the sensing apertures (which may be referred to as the sensing position) to the printing solenoid (the position of which may be referred to as the printing position) before the printing operation is effected.

It is understood that individual control circuits similar to the one shown in Fig. 4, are provided for each sensing aperture I 2 or sensing position provided in the device.

The sensing apertures I2 shown in Fig. 2 are shown disposed horizontally with respect to the feeding of the paper. In certain cases, where the paper is fed at a high rate of speed and depending upon the type of paper web to be tested the horizontally disposed apertures may be subamuse jected to clogging with paper lint. Such conditions, of course, might reduce in time the amount of light transmitted to the photocells to such a degree that the photocell and amplifying system might fail to detect the foreign substances in the web.

To overcome such conditions the type of sensing grill shown in Fig. 3 may be employed. Each sensing aperture comprises a plurality of openings 30 formed at an acute angle with respect to the opaque frame member. Upon detection of a foreign area, the area as it is fed by the openings 80 causes several light changes to be effected on the photocell thus causing a number of electrical impulses to be impressed upon the input circuit of the associated amplifier unit. In addition to this desirable electrical response. the angularly disposed openings do not clog as readily as the single horizontal aperture shown in Fig. 2.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claim.

What is claimed is:

A device of the character described comprising a sensing station and a marking station, means for feeding continuously past the said stations a web of light permeable paper substantially free from foreign areas, said stations spaced a pre-determined distance apart lengthwise of the web so that a pre-determined section thereof passes the sensing and marking stations successively in the order named, means at the sensing station for sensing the foreign areas comprising an opaque member, over which the said web is fed, having a plurality of individual apertures formed therein at substantially acute angles, and spaced transversely to the direction of the feeding of the web, a light source opposite one side of the web and light responsive means opposite the other side of the web and apertures, means to direct the rays of light to the web at a point opposite the said apertures and light responsive means, the formation of the apertures at the said acute angles preventing sufficient amounts of paper lint to collect therein to reduce the amount of light transmission therethrough, marking means at the marking station disposed in close proximity to the web, means controlled by the light responsive means whenever a foreign area is presented to the sensing station to modify the amount of light transmitted to the light responsive means for rendering the marking means operative, and means for delaying the operation of the marking means until the sensed foreign area is fed to the marking station whereupon the location of the said foreign area on the web is marked.

OI'IO WEITMANN. 

